Indicating signal



July 3, 1945.

H. F. RE MPT INDICATING SIGNAL Filed June 3, 1945 INVENTO Y Henry -F. Rempt Agent adjustment or other attention.

Patented July 3, 1945 S PATENT OFFICE mmcn'rmc SIGNAL Henry F. Rempt,

Van Nuys, Calii'., asslgnor to ibockheed Aircraft Corporation, Burbank, Calif.

Application June 3, 1943, Serial No. 489,515

4 claims. (Cl. 177-329) This invention relates to visual signals for instrument panels and switch boards and finds its principal application to instrument panels of airplanes and the like aircraft.

Heretofore, in aircraft instrument panels, signal lights have been employed primarily to warn the pilot or flight engineer of the conditions of various apparatus within the aircraft. For example, signal lights have been employed to warn the pilot of the position of the retractable land-, ing gear and landing flaps when the engine throttle is closed. Signal lights have-also been em- Ployed to warn of failures of pressure in the fuel, oil, oxygen, and various hydraulic lines, and to perform numerous other vital services. Such signal devices have heretofore usually comprised small incandescent electric-lights housed in suit-.

able receptacles and positioned behind small, faceted, colored glass bezels located at suitable points in the various instrument panels.

Disadvantages of the incandescent electric types of signal devices were primarily that they were too fragile to withstandthe prolonged engine vibration-and the shock of cannon and machine gun fire in combat aircraft and were otherwise subject to frequent failure due to burning out of the filament. Moreover, because of resides in-providing a signal device, the signal of which may be viewed by an observer throughout a wide range of angles.

The invention in its general aspects resides in an electro-magnetically controlled fluorescentradioactive-luminescent and reflecting signal body adapted to be energized by visible light, so-

.called black light or ultraviolet light, or by in:- corporated radioactive material.

the brilliance of the points of. light which they produced they had a blurring or blinding effect upon the eyes, interfering, with clear vision, particularly at night. Attempts have been made to overcome this latter disadvantage by providing manually adjustable apertures or shutters on the visible portion of the signal device by means of which the emitted light could be dimmed or adjusted to suit the lighting conditions prevalent at a given time. This manual dimming adjustment, however, introduced a further disadvantage and hazard by reason of the fact that when the signal light was dimmed to an extent suitable for night operation in a darlrened compartment, if subsequent readjustment were neglected or forgotten,

Other objects, advantages, and features of novelty will be evident hereinafter.

In the drawing in which like reference characters refer to similar parts,

Figure 1 is an enlarged side view in partial cross-section of the signal device assembly;

Figure 2 is a cross sectional view taken on line 2-2 of Figure 1;

' Figure 3 is'a rear-end view of the signal device;-

Figure 41s a front-end view of the signal device as it appears when energized;

Figure 5 is a cross-sectional view taken-on line 5 -5 of Figure l; and

Figure 6 is a front-end view of the signal device as it appears when de-energized.

Referring nowto the drawing, W is a tubular case or housing composed of a ferromagnetic metal such as soft iron provided with threads on the forward outside portion atll and carrying at the rear end a pair of diametrically opposed inwardly extending stubs i2 and it which constitute pole pieces of the magnetic actuating mechanism hereinafter described.

The forward end of the tubular housing is closed by means of a relatively thin convex or conical shaped transport cover member it secured in place by means of a knurled compression nut i5 which makes threaded connection with threads ii. The rear end of the case it is closed by a disc ,shaped cap it retained in position by as it was apt to be, the warning light then often could not be seen in the brilliancy of daylight.

Objects of the invention are, therefore, to overi come the disadvantages of the incandescent signal devices heretofore employed paiticularly in relation to their employment in aircraft instrument panels and to provide a signal device which will be relatively free from the types of failures associated with incandescent lights, and will be non-blinding andequally visible in daylight on night conditions without the necessity of manual a pair of screws ii and it which pass through the cap body and make threaded connections at it andEd in threaded holes'in the housing stubs "Hand 83.

A spool shaped electromagnet is snugly con- .tained within the housing msaid electromagnet comprising an axially positioned tubular core 2i of ferromagnetic material supported at its forward end mainly by an integrally formed flange 22. A plurality of turns of insulated conductor Another object and advantage of the invention 24 are wound on the core fivbetweeninsulating' annular shaped end pieces 25 and 26 and the conductor ends 21 and 28 brought eut' through the terminal bushings 29 and 30 forming an in- I tegral part of the beforementioned cap .66.

A rod 32 rotatably supported upon a pair of it may be rotated leads 2! and brass bushings 33 and 34 extends concentrically through and projects fromthe ends of the tubular core 2|, and said rod carries fixed to the rearwardly' extending end a diametrically positioned armature bar 35, and threaded onto the forward end a conical shaped signal element 36.

The armature bar 35 which may be made of soft iron is limited in the angle through which by the X shaped recess 31 formed 'within the inside end surface of the cap l6. Thus the armature may rotate from the position indicated in dotted lines at 36 to the position in alignment with the stub pole pieces l2 and I3 as shown in solid lines at 362 The armature 35 is normally retained in the position shown in dotted lines at 38 by means of the torsion of a spiral hair spring 40 acting through the rod 32 to which the said armature is fixed. The inner end of the hair spring 46 is attached to a lock nut 4| threaded on the forward end of the rod 32 and the outer end is attached to a pin 42 carried in the core flange 22.

The forward conical surface of the signal element 36 carries a plurality of zonalareas of fluorescent or luminescent material arranged to appear in the form of four equally spaced clr-' cular sectors as viewed from the front as best shown at 43-46 in Figure 5. The so-called circular sector zones of fluorescent material are circumferentially. spaced apart edge to edge at distances equal to their widths.

The conical shaped cover member l4 which,,

as before stated, may be composed of a transparent material, is rendered opaque at all other points except at four equally spaced windows 48-5l which are-adapted to exactly match in size, shape, and relative circumferential position the said four fluorescent zones 43-46, whereby the fluorescent zones will be entirely visible when aligned'with the transparent windows 48-5l in the cover [4 as shown in Figure 4 and entirely a hidden behind the intervening opaque spaces between the windows in the cover as shown in- Figure 6 when the signal element 36 is rotationally displttced one-eighth of a turn or 45 from such aligned position.

A pair of annular nuts 63 threads ll serve to adjustably' retain the case M of the unit in an aperture of suitable diameter in an instrument panel sheet 55.

In operation the conductor leads 2'! and 26 extending from the windings 24 of the electromagnet may be connected in series with a suitable source of electric current and suitable contacts or switching devices associated with and actuated by the mechanism for which signal impulses are desired. For example the conductor 28 may be connected by way of a suitable source of direct .current such as a battery to electrical contacts actuated by the combined action of the engine throttle and the retractable landing gear mechanism so that if the throttle is closed when the landing gear is still retracted the electrical supply circuit will be completed through the windings of the signal at 35 in alignment with Said pole pieces. In this position the fluorescent zones 43-46 on the conand 64 carried on -are completely hidden from view as shown in The conical cover element I4 is preferably formed of a relatively thin section of 'a, suitable plastic material transparent to both visible and ultraviolet light such as for example a methyl methacrylate resin of the types known as lucite while the signal element 36 and cap [6 may be formed of metal or any suitable plastic such as cellulose acetate or vinyl resin. The cover element l4 may be rendered opaque at all points excent at the transparent windows by means of an internally or externally applied coating of black lacquer or by pigments impregnated in the plastic material. The signal element 36 and all other Parts of the device also are preferably colored black at all points except the beforementioned fluorescent areas. 1

The fluorescent material fluorescent paints or color of fluorescence desired and they maybe applied in a thin layer by suitable means to the said areas of the signal element minous paints may be obtained from several sources as disclosed in the Department of Commerce, National Bureau of Standards, Circular maybe-one of several Letter LC 678.

Such materials are excited to fluorescence by sunlight and various artificial lights, but for use at night in a darkened compartment the fluorescent signal element' is preferably energized by means of a suitable ultraviolet lighting unit. The fluorescent material on the signal element may also be rendered self-luminous by incorporating a minute quantity of radioactive material in its composition as is well known. A small amount device to give a warningthat the aircraft is of admixed pigment of a suitable color corresponding to that at which the material fiuoresces is desirable when the instrument may. be viewed totally or partially by reflected light. A particular feature of the signal device of this invention resides in its which adapts it to be readily installed in switch board and instrument panel bezel apertures substantially interchangeable with the incandescent light types or signal devices heretofore employed for such purposes; Another importantnnd novel feature of the instrument resides shape of the signalling surface and its projection forward from the body of the instrument into the convex transparent cover whereby it may be readiLv viewed from a wide range of angles.

The size of wire and number of turns employed in the electromagnet will depend upon the voltage of "the electrical system to which it is to be lacquers depending upon the l4. Suitable lusmall diameter and shape 1 in the angular any position and under all lighting conditions without adjustment at any time, either in the daylight by combined fluorescent and'reflected light, or at night by ultraviolet light excitation or in case of failure of such excitation by its radioactively excited luminosity.

The foregoing is illustrative of the apparatus of the invention and is not to be limiting. The invention includes any equivalent apparatus within the scope of the claims.

I claim:

1. A signal device comprising a housin .an electromagnet in said housing, an armature in said housing, means for applying a restoring force to said armature, said armature being adapted to be moved between limits respectively in response to energization of said electromagnet and the restoring force of said means, a curved transparent cover having spaced opaque zones thereon, said cover being attached to and extending outward from the forward end of said housing, a fluorescent signal surface having spaced fluorescent zones thereon matching the opaque zones of the cover, said surface extending into the curved space back of said cover, said signal surface being adapted to be moved between exposed and hidden positions back of said cover in response to said movement of said armature,

2. A signal device comprising a housing, an electromagnet in said housing, an armature in said housing, means for applying a restoring force to said armature, said armature being adapted to be moved between limits respectively in response to energization of said electromagnet and the restoring force of said means, a curved cover having spaced transparent zones therein, said cover being attached to and extending outward from the forvward end of said housing, afluorescent slB al surface having spaced fluorescent zones thereon corresponding to the transparent zones in the cover, said surface extending into the curved,

space back of said cover, said signal surface being cover having opaque and transparent zones, a

convex fluorescent signal surface extending into the space immediately back of said cover, said signal surface having spaced fluorescent zones corresponding to theopaque zones of the cover and being adapted to be rotated between exposed and hidden positions backof said cover in response to said movement of said armature.

d 4. A signal device comprising a housing, an

electromagnet in said housing, an armature in said housing, means for applying a restoring force to said armature, said armature being 1 adapted to be moved between limits respectively in response to energization 'of said electromagnet and the restoring force of said means, a convex transparent cover having alternate opaque and transparentzoues attached to and extending outward from the forward end of said housing, a

convex fluorescent signal surface having alternate fluorescent and non-fluorescent zones and.

extending into-the space immediately back of said cover, said fluorescent zones on said signal surface being adapted to be rotated between exposed and hidden positions back of said opaque and transparent zones on said cover in response to said movement of said armature.

may F. 

